Cardiovascular risk factors and hearing impairment: a non-automatic correlation

Abstract

Background: In the literature the association between common cardiovascular risk factors and/or major events and inner ear diseases has been widely considered. Despite the controversial related results, a recent review underlines that while a direct and causal correlation between cardiovascular risk factors and hearing impairment is lacking, the former are thought to have an influence on hearing acuity: this should imply some correlation between arterial conditions and inner ear function.

Aims: Aiming at verifying the reliability of the correlation between arterial conditions and inner ear function, the hearing function of a population with metabolic syndrome and a population without metabolic syndrome were matched.

Methods: All the examined subjects were enrolled within the Brisighella Heart Study, in order to obtain a detailed knowledge of the cardiovascular and metabolic parameters. 142 subjects were enrolled, including 89 healthy subjects and 53 affected by metabolic syndrome, having ruled out those cases associated with external and/or middle ear pathologies, or unilateral sensorineural hearing loss or with a history of previous ototoxic drugs and ear surgery. Among the examined parameters was arterial stiffness, as evaluated by means of the Vicorder® device with a non-invasive procedure, which had not previously been considered in relation to labyrinthine function.

Results: The lack of any statistically significant correlation between common cardiovascular risk factors and hearing deterioration, as emerged from the study, has a particular significance.

Conclusions: The inference from this result is that the relationship between the systemic circulation and inner ear conditions must be more complex than frequently considered.

Keywords:

• Hearing loss
• metabolic syndrome
• cardiovascular risk factors

Acknowledgements

We particularly acknowledge Marina Giovannini and Elisabetta Rizzoli for their support to the Brisighella Heart Study laboratory activity and Marcella Cagnati for her work on data managing. We also sincerely thank the Faenza public health district and all the General Practitioners of Brisighella for their continuous support to the study.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all the individual participants included in the study.

Disclosure statement

We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. No author has a specific conflict of interest in the publication of this paper.

Funding

This work has been conducted with funding of the Italian Ministry for University and with a grant from the ‘Fondazione del Monte di Bologna e Ravenna’ (Bank foundation).